The Air Jet Loom (AJL) is becoming increasingly popular as a progressing loom as well as the Water Jet Loom (WJL) process. AJL has become more popular in recent times because it is more suitable for cellulosic filament yarns such as acetate and rayon which are weakened by water.
Generally, cellulosic filaments for warp yarns are sized before weaving with AJL process. There is not much difficulty compared to conventional looms (shuttle looms) because the process is conducted in dry air as opposed to WJL wherein water is used.
But as for cellulosic filaments for filling yarns, the feeding method is a special one by air jet and the conventionally produced yarns result in poor yield or quality of woven products by their unsuitable property for air jet.
As the air jet is diffusible, it has poor feeding ability comparing to that of a water jet, which is indiffusible. Irregular forms of filling yarns on the line of yarns affects the uneveness of feeding ability, and there exist several problems as follows:
Filling yarns typically do not flow well in air jets and cannot be inserted at required operating speeds.
Filling yarns are tangled by air jet and monofilament is broken.
To solve these problems, flyability is needed for filling yarns in AJL process. The word "flyability" means the easy flowing of yarns in an air jet. High quality yarns for AJL process must meet the need of the flyability. In other words, yarns must be susceptible to being inserted stably under a regular and low air pressure.
The improvement of yarns' flyability is the most important problem in pursuit of good yield in AJL process.
In the conventional methods for finishing, lubricants of mineral oils are typically used as a main component and non-ionic and anionic surfactants are added as emulsifier and antistatic agents. Mineral oils are effective to decrease the friction between fibers and contact surface, i.e. guides, pooling drums, etc. Today, mineral oils having low numbers of carbon atoms and low viscosity at about 5.7 cst. are generally used for this purpose.
But finishes consisting mainly of mineral oils of low viscosity volatilize due to volatilization of residual acetone contained in yarns. Such residual acetone will evaporate during storage of yarns before weaving. This causes the change of the finishes' formulation on yarns or the irregular distribution of finish on yarns between the outer and the inner layers of cheeses which, in turn, results in the irregularity of friction in the weaving process. Thus the serious defects at weaving slack and filling entangling, occur and cause reduced quality of woven fabrics.